One typical group of organosilicon compounds is silane coupling agents. The silane coupling agents have two or more different functional radicals in their molecule, and serve as a chemical bridge to bond an organic material and an inorganic material that would otherwise be difficult to bond. In the silane coupling agent, one functional radical is a hydrolyzable silyl radical which forms a silanol radical in the presence of water. This silanol radical, in turn, reacts with a hydroxyl radical on the surface of inorganic material to form a chemical bond to the inorganic material surface. The other functional radical is a reactive organic radical such as vinyl, epoxy, amino, (meth)acrylic or mercapto and forms a chemical bond with organic materials such as various synthetic resins. Due to these attributes, the silane coupling agents are widely used as modifiers, adhesive aids, and various other additives in organic and inorganic resins.
Especially, (meth)acrylic radical-containing silane coupling agents are used as modifiers for (meth)acrylic resins, adhesive aids in (meth)acrylic polymer based adhesives, and the like. The (meth)acrylic radical-containing silane coupling agents generally refer to those in which a (meth)acrylic radical is linked to a hydrolyzable silyl radical via an alkyl chain. Only a few silanes have a linking chain containing an amide or urethane bond whereas no silanes having a linking chain containing a urea bond are known.
(Meth)acrylsilane coupling agents having an amide bond are effective as adhesive aids because of intermolecular hydrogen bond by the amide bond and also compatible with resins because of their polarity. However, a problem arises with these silanes since they are generally prepared by dehydrochlorination reaction of silane coupling agents having an amino radical with (meth)acrylic acid chloride. It is difficult to remove chlorine from the resulting silanes. Such silanes can often cause degradation over time in various, applications.
There is a desire to have (meth)acrylsilanes which are highly soluble in various solvents, highly compatible with resins, substantially chlorine free, and effective as additives and modifiers.
Citation List
Patent Document 1: JP-A H05-4994
Patent Document 2: JP-A H05-25219